This invention relates to an ignition timing control system for an outboard engine and more particularly to an engine control for an outboard engine that will maintain the running condition of the engine uniform regardless of the trim adjusted angle.
As is well known, outboard motors are normally mounted on the transom of a watercraft and are adjustable through a plurality of trim adjusted ranges so as to insure that the angle of attack of the propeller is proper for all running conditions. Although the trim adjustment relative to speed of the watercraft improves the efficiency of the propulsion unit, the adjustment of the trim of the outboard motor can effect its running characteristics. For example, if the engine is employed with a conventional type of carburetor having a float bowl that maintains a uniform head of fuel for carburation purposes, the fuel head will vary as the trim adjusted condition changes and the air/fuel ratio can vary with the trim adjusted position. Of course, variations in air/fuel ratio dictate changes in spark timing in order to insure optimum engine performance. However, the spark timing of an engine is normally controlled as a function of speed and/or load.
It is, therefore, a principal object of this invention to provide an improved control for an outboard motor wherein the running of the engine is stabilized depending upon the trim adjusted condition of the outboard motor.
It is a further object of this invention to provide an engine control for an outboard motor that insures efficient running of the engine under all trim adjusted conditions.